Ore reducing machine



' A 1939- H. HARDINGE 2,171 2 ORE REDUCING IACHINE Filed July 18; 1956 j. 2 Sheets-Sheet 1 H. HARDINGE ORE REDUC ING MACHINE Filed July 18, 1936 2 Sheets-Sheet 2 Patented Aug. 29, 1939 'Harlowe Hardinge,

York,

Pa., assignor to Hardinge Company, Incorporated, York, Pa, a

corporation of New York Application July 18, 1936, SerialNo. 91,402 2 Claims." (01. 83-46) This invention relates to ore reducing machines of the type in which the material is ground or pulverized in a rotating drum supported by hollow or tubular trunnions.

An oject of the invention is to provide an im;- proved ore reducing machine having a drum formed with a plurality of buckets so constrcted that one side of the buckets constitutes means for lifting the material in the bottom of the drum upwardly a predetermined height, and the other portion of the buckets constitutes means for receiving the impact of the material discharged from the buckets at the upper portion'of the drum.

Another object of the invention is to-provide an improved ore reducing machine having a revolvable drum so constructed that a portion of the material fed into the machine for grinding is carried, by pockets disposed around the end walls of the drum, and certain of the pockets are provided with means for separating the fines from the coarser particles of the ore segregated 1 from the main body of the ore undergoing reduction in the machine.

Another object of the invention is to provide an improved ore reducing machine having'a revolvable drum so constructed that the ore is caused to drop on impact mediums in a continuous circuit, and in which means are provided for segregating a portion of the ore within the drum from the main body of the ore undergoing reduction in the machine, so that the finer particles on the segregated portion of ore can be separated and removed from the machine.

Another object of the invention is to provide an improved ore reducing machine in which a classifying means is combined with the reducing means so that the fines are removed from the circuit and only the coarser particles which require further reducing are retained in the circult, whereby great economy in operation is obtained.

Another object of the invention is to provide an improved classifying system for ore reducing machines of the above type in which means are provided within the machine for partially classifying the material and additional classifying means are provided outside of the machine for the final classification of the material so as to improve the character of the product produced andincrease the efficiency of the machine,

Another object of the invention is to provide an improved ore reducing machine of the character mentioned, which is simple in construction and reliable and exact in function under all conditions of service.

The invention also comprises certain new and useful improvements in the construction, arrangement andjcombination oi the several parts 5 of which it is composed, as will be hereinafter more fully described and claimed.

In the accompanying drawings: Figure 1 is a central vertical transverse section through an ore reducing machine embody- 1 ing the invention;

Fig. 2 is a vertical longitudinal section taken. on the line 2-2 of Fig. 1; and Fig. 3 is a section taken on Fig. 1 and Fig. 2.

Referring to the drawings, the improved ore reducing machine comprises a cylindrical drum having end walls l2 and I3.

The end wall I2, which is at the feed end of the drum, has a hollow trunnion l4, and the end 20 wall |3,, which is at the discharge end of the drum, has a hollow trunnion I5.

The trunnions l4 and |5 are mounted for rotation on roller bearings 35 carried by a suitable supporting structure I6. 25

Any suitable mechanism may be employed for. rotating the drum In the present instance the operating mechanism comprises an electric motor I1, the shaft of which carries a gear l8 that is operatively connected to a 30 sprocket I9 fixed to the trunnion l5 of the drum by a chain 20.

Arranged around the interior of the line 3-3 or the peripheral wall 2| of the drum H is a series of members 22.

' combined function of lifting the ore undergoing reduction in the drum upwardly from the bottom portion of the drum while the drum is being rotated, and means for receiving the impact of the ore when the ore falls to the bottom of the 4 drum after being elevated.

In the present embodiment of the invention, as shown in the drawings, the members 22 comprise a radial portion 23 which extends inwardly from the outer peripheral wall of the drum 2| a suitable distance. These radial portions 23 are, as shown in Fig. l, uniformly spaced apart, and function as lifters or buckets for carrying the mlaterial .upwardly from the bottom of the drum Extending from the inner end of the radial portion 23 of each member 22, outwardly towards the peripheral wall 2| of the drum and terminat-,

lli

members 22 are spaced a suitable distance from the end walls l2 and I 3 of the drum.

The members 22 may be formed from any suitable material and can be fastened to the peripheral wall 2| ofthe drum by any suitable method, such as welding.

Encircling the trunnion l4. and secured to the end wall 12 of the drum is an annular member constituting a shroud 2T.

Also carried by the end wall I3 of the drum is another annular member or shroud 28.

The shrouds 21 and 28 are frusto-conical in cross section, as shown in Fig. 2, said shrouds having their wall inclined' at an angle. so that the shrouds taper outwardly from the end walls 12 and I3, respectively.

The shrouds 2'! and 28 are, at their inner edge portions, slightly less in diameter than the interior diameter of the members 22, andthe inner edges of the shrouds are spaced apart a distance somewhat less than the length of the members 22, so that the inner portions of the shrouds overlap the extremities of the members 22 a suitable distance, asshown in Fig. 2. The purpose in constructing the parts in this manner will be hereinafter more fully described.

In the drawings, the shrouds 21 and 28 ar shown as composed of two pieces of sheet metal, such as plate steel, the inner portion being of less width than the outer portion and serving as means for reinforcing the outer portion adjacent the end walls of the. drum.

The shroud 21 surrounds the inlet trunnion M of the machine, while the shroud 28 surrounds the outlet trunnion I5; I

The construction of the shrouds 21 and 28 is such that a Vshaped annular compartment is formed at each end of the drum.

A plurality of flat plates 28, which extend at an angle from the ends of the members 22 outwardly to the end walls of the drum II, divide the above referred to compartment intoa series of pockets 26, the purpose of which will behereinafter more fully described.

Openings 3!) are formed at intervals around the shroud 28. Overlying'each of said openings is a screen 3|. Underlying each opening 30 is a chamber 32, the bottom of which is inclined downwardly and outwardly towards the end wall I3, as shown best in-Fig. 2. Extending from the bottom of the chamber 32, is a discharge tube 33. The screening chamber 32 is secured to the shroud 28 and side'plates by a reinforcing plate 34.

' In Fig. 1 of the drawings the shroud 28 is shown as being provided with four chambers 32 and tubes 33, and in Fig. 2 the above elements at the lower portion of said shroud are omitted, so asto show the construction of the shroud proper.

Extending through the trunnion 15 of the machine, is a discharge pipe 36, which supports at its inner end a stationary chamber 31. 'The chamber 31 has an open upper portion or top.

Covering the top of the chamber 31 is a screen 38 which is arcuate in front elevation as seen in Fig. 1, and which is inclined at a suitable angle as shown in Fig. 2.

The chamber 31 is disposed slightly above the axis of the drum II and the screened top thereof underlies the ends of the tubes 33 as the same travel around during operation of the machine.

The outer end of the discharge tube 36 terminates within a classifier device 48, only the end portion of which is shown in Fig. 2. Any suitable'type of classifier 40 may be employed. In the present instance I have shown a classifier along the general lines of the rotary wet classifier shown in my Patent No. 1,917,300, granted July 11, 1933. Since the construction and operation of the classifier 40 is well understood it needv not be repeated in the instant case. However, leading from the end of the classifier 40 adjacent to the ore reducing machine is a trough or launder-4|, by which the oversize material which has been classified is returned to the drum l l for further reduction.

In the operation of the device the ore to be ground is fed into the drum II by means of a feed trough or launder 43 projecting into the trunnion M. The material falls into the buckets in the bottom of the drum in the manner shown by the broken lines and arrows in Fig. 2,. the material being directed towards the intermediate or central part of the buckets by the inclined surface of shroud 21. The radial portion 23 of the buckets raises the'material, as shown in Fig. 1,. and the material gradually .discharges from the buckets after being raised to a point above the center of rotation of the drum. The material thus discharged from the buckets drops against the arcuate portions 24 of the members 22 and collects in a bed in the manner illustrated, in Fig. 1.

During the operation of the machine a portion of the material collects in the pockets 26 as the mass of material is raised. Due to the construcmixes with the material spilling out of the pockets 26, so that a considerable intermingling of the different portions of the ore takes place while the drum is rotating.

Referring to Fig. 1, it will be noted that a bed of material is shown on the member 24 in bucket A, which bucket is disposed at a considerable elevation above the bottom of the drum. The presence of this material in this portion of the machine is due to the fact that the material retained in the pockets 26 at the ends of the above bucket A spills outwardly over the edge of the member 29 and inclined walls of the shrouds 21 and 2B, and thus provides a bed on the member 24 for the ore falling into bucket A, as the same moves downwardly toward the bottom of the drum during operation of the machine.

When the material spills out of the pockets and falls over the lip provided by the inclined walls of the shrouds 21 and 28, the same is directed towards the center of the drum, as shown by the dotted lines in Fig. 2. This action causes the ore to be evenly distributed in the buckets and prevents the ore from hitting heavily against the end walls of the drum. In. this way the material moves around the drum in a closed circuit. Ex-

cessive wear of the end walls and internal parts of the drum is prevented, and any tendency of the fine and coarse sizes to segregate is eliminated.

During rotation of the-drum, the fines .in the material within the pockets 26 near the top of the drum fall through the screens 3!, and such fines are directed towards the screen 38 by the tubes 33. The fines then pass through the screen 38 and collect in the chamber 31 from which they are discharged through tube or launder 36 into the classifier 4D. In this way the ore will not pass out of the circuit until it is fine enough to sift through the screens 3| and 38 at the discharge end of the drum.

The fresh feed entering the drum through the shroud 2'1 intermingles with the ore undergoing reduction which is carried by the members 22, and as the result of this interminglingof ore the finer particles are pushed forwardly towards the discharge end of the drum. In this way there will be a preponderance of finer particles of ore.

- at the discharge end of the drum.

The finer particles together with the water which are delivered to the classifier 40 by the tube or launder 35, are subjected to the classifying action whereby the coarser particles are returned to the drum ll through the trough or launder 4| for further reduction, and the fines are delivered from the opposite end (not shown) of the classifier 40.

From the foregoing it will be noted that by my invention I have provided an improved ore reducing machine in which means are provided within the drum of the machine for partially classifying the ground material and additional classifying means are provided outside of the drum H for the final classification of the material. In actual operation of a machine constructed according to my present invention, the character of the product has been improved considerably over the product of other ore reducing machines heretofore in use, and due to the construction and arrangement of the parts and the manner of grinding the ore in a closed circuit Within the drum II, the power consumption and the frictional wear on the interior of the drum of the machine has been reduced to a minimum, so. that the machine can be successfully used for reducing lower grades of ore on a paying basis than would otherwise be possible. In this connection it should be' noted that the shrouds 21 and 28, together with the pockets 28 formed by the inclined plates 29, perform the dual function of preventing the ore dropping from the buckets, causing excess friction and wear on the ends of the drum, and these elements also help lift a portion of the ore at the extreme ends of the buckets up and over the top of the drum to help form a protective layer on the back of the buckets fwhich receive the greatest impact of the dropping ore.

From the foregoing description of the operation of the improved machine it will be understood that when so desired the machine can be constructed with only one'cf the shrouds 2.1, 28, and that other modifications can be made in the construction of the machine without departing from the scope of the invention as covered by the claims appended hereto.

Having thus described my invention what I claim is 1. In an ore reducing machine, a revolvable drum comprising end walls and a peripheral wall, buckets arranged around the interior of the.

peripheral wall of the drum and midway between the end. walls of the drum, said buckets having their end extending towards the end walls of the drum, an annular frusto-conical shroud mounted on the interior of an end wall,'the inner edge-portion of said shroud abutting the end of the drum being of less diameter than the diameter of the outer edge portion ofthe shroud, the shroud extending inwardly from the end wall and vertically overlapping the ends of the buckets, a plurality of plates mounted on the interior of the end wall of the drum and contacting the shroud and the ends of said buckets and dividing the end portion of the drum into a plurality of compartments for reception of ore, means formed at'intervals in the shroud for removing a portion of the ore from the compartments, and stationary means underlying said ore removing means for discharging from the machine the ore thus removed from the compartments.

2. In an ore reducing machine, a revolvable drum comprising a peripheral wall and end walls providing central openings through the drum, buckets arranged around the interior of the peripheral wall and midway between the end walls, said buckets having open ends extending towards the end walls of the drum, an annular frusto-conical shroud having its apex portion secured to the interior of an end wall and its base portion vertically overlapping the ends of the buckets, a series of fiat plates mounted on the interior of the end wall of the drum and'contacting the shroud and the ends of said buckets and dividing the end portion of the drum into a plurality of compartments for reception of ore,

' ore discharged from'said shroud screening chambers, and means connected to said stationary screening chamber for discharging from the ma.- chine the ore thus removed from the compartments.

HARLOWE HARDINGE. 

